Digital mobile multimedia broadcast technologies and related standards have been developed rapidly in recent years, such as Digital Video Broadcast Handheld (DVB-H for short) in Europe, Media Forward Link Only (MediaFLO for short) in America, and BroadCast and MultiCast Services (BCMCS for short) based on mobile cellular, and so on. A digital mobile multimedia broadcast network provides various services for terminal users, such as advertisement, weather forecast, news, sports show, variety show, multimedia broadcasting play, movie and other programs, and the users can select the programs provided by a mobile multimedia player according to their preferences.
In short, the so-called mobile telephone TV service refers to a service which enables a user to watch TV programs via a mobile telephone terminal for mobile communication. As an emerging service, a mobile telephone TV is advantaged in portability, mobility and privacy compared to a conventional television that is placed in a living room for the share of the whole family. With the popularization of mobile data service and the expansion of mobile telephone video function, the mobile telephone TV has gradually stepped into people's life. With the improvement of people's living standard, consumption demands of people become more diversified and fashionable, and watching TV programs on a mobile telephone has become a fashion and will become a life-enjoying way of people.
From the point of the development of broadcast TV service, the conventional broadcast TV technology has been developed rapidly from simulation technology to digital technology, the TV signal receiver has also been developed from a common desktop TV to diversified terminals such as mobile TV, vehicle-mounted TV and handheld TV; from the point of the development trend of mobile communications, it becomes possible to watch TV programs via a mobile telephone terminal as the data transmission capacity of a mobile communication network has been greatly improved and the terminal manufacturing technology is being perfected constantly. The technical progress in these two aspects opens a path for receiving high-quality video programs via a mobile telephone terminal, thus the rigid boundary between the two industries begins to disappear, and as a consequence, a new service mode of mobile telephone TV is developed.
Emergency broadcast, which is a way of notifying the public of emergencies via a broadcast communication system, provides a rapid and efficient way of notice in the cases of emergencies such as natural disaster, accident, public health and social security, or in the cases in which heavy casualties, property loss, ecological environment destruction, serious social harm and threat to public security are brought about or may be brought about. As more and more attention is paid to all kinds of emergencies in the country and various public emergency plans are proposed, as a broadcast technology with a large number of online users, it is extremely necessary to provide an emergency broadcast service. The mobile telephone terminal capable of receiving emergency broadcast messages can receive the emergency broadcast messages sent from an emergency broadcast system.
FIG. 1 is a structure diagram of a mobile multimedia broadcast channel frame, as shown in FIG. 1, a plurality of multiplex frames constitute a broadcast channel frame, and each multiplex frame consists of a multiplex frame header, a multiplex payload and a filling part.
For example, if it is determined that 1 second is a multiplex period, which is divided into 40 time slots, 25 ms is a multiplex unit. Logical mapping of multiplex frames and time slots is determined by system configuration.
One multiplex frame corresponds to one control logical channel or service logical channel. A multiplex frame identity MF_ID, which is ranged from 0 to 39, with the largest number of 39, is distributed to each multiplex frame, wherein the multiplex frame with MF_ID=0, which is mapped to a control logical channel, is used for transmitting system control information, and the multiplex frame with an MF_ID not being 0, which is mapped to a service logical channel, is used for transmitting service information.
As shown in FIG. 2, the multiplex frame with a multiplex frame identity of 0 is used for bearing control information, the multiplex frame payload in the multiplex frame includes a plurality of control information tables, and each multiplex sub-frame consists of one control information table. In the current mobile multimedia broadcast specification, an emergency broadcast service is placed in the control information table with a table identity of 0x10, in the control information multiplex frame.
As shown in FIG. 3, there is an ‘emergency broadcast flag’ in the multiplex frame header, the multiplex frame with a multiplex frame identity of 0 carries an emergency broadcast when the flag is not 0.
In existing technologies, if an emergency broadcast message receiving chip is installed in a mobile telephone, the emergency broadcast message receiving chip can be started to receive an emergency broadcast message if the mobile telephone is provided with a mobile telephone TV application. The user can receive an emergency broadcast message only after entering the mobile telephone TV application; the user cannot receive an emergency broadcast message when not entering the mobile telephone TV application. If there is not a mobile telephone TV application in a mobile telephone, then the mobile telephone cannot receive an emergency broadcast message. When there is a mobile telephone TV application in a mobile telephone and the user enters the mobile telephone TV application, the mobile telephone performs an uninterrupted detection to determine whether there is an emergency broadcast message, and displays the detected emergency broadcast message to the user when detecting an emergency broadcast message.
Existing technologies have the following disadvantages:
1. the mobile telephone terminal without a mobile telephone TV application cannot receive an emergency broadcast message;
2. the mobile telephone terminal cannot notify the user of an emergency broadcast message timely in an effective period of time, thus failing to perfectly achieve the purpose of providing a rapid and effective way of notice by the emergency broadcast;
3. the mobile telephone terminal consumes a considerable amount of power as it detects emergency broadcast messages uninterruptedly.
Therefore, it is necessary to provide a rational and convenient method for a user to receive an emergency broadcast message when the mobile telephone is powered on.